Method for enriching iridium from high-acidity high-salt iridium-containing solution

Abstract

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a method for enriching iridium from a high-acidity high-salt iridium-containing solution. The method comprises the following steps: step 1, ion exchange resin adsorption: adsorbing a feed liquid through LS-32 chlorine resin, and sending the obtained liquid subjected to ion exchange adsorption to a sample for detection; step 2, pure water washing: pure water is selected as a washing agent to elute other metal ions except iridium, and iridium-loaded resin is obtained; and 3, high-temperature ashing is conducted, specifically, the iridium-loaded resin is subjected to high-temperature ashing, and the iridium-enriched slag is obtained. According to the method, the low-content precious metal iridium existing in the high-acidity high-salt solution is separated from other high-content metal ions by adopting an ion exchange method, the iridium content in the solution after ion exchange adsorption is lower than 8 ppm, the iridium adsorption rate is larger than 95%, the iridium content in the enriched iridium slag is higher than 2000 ppm, and the high-content metal ions in the solution after ion exchange adsorption are separated from other high-content metal ions. The comprehensive recovery of low-content iridium in the high-acidity high-salt hydrochloric acid solution is successfully realized.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrometallurgy, and in particular relates to a method for enriching iridium from a high-acidity and high-salt iridium-containing solution. Background Art

[0002] Iridium, a precious metal of the platinum group, is an important material for modern industry and national defense construction due to its unique physical and chemical properties. It is widely used in aerospace, microelectronics, petrochemicals, hydrogen energy and other fields.

[0003] my country's platinum group metal resources are extremely scarce, with proven reserves of just 342 tons, representing 0.48% of the world's total. Annual production of platinum group metals in my country is less than 5 tons, far from meeting growing consumption. Therefore, developing new technologies for recycling platinum group metals is of vital practical significance.

[0004] The method of capturing precious metals with base metals has been widely used to recover precious metals from various resource materials and secondary resources. The iron capture method, in particular, demonstrates superior capture capacity for the precious metal iridium and is therefore increasingly being adopted by companies for the pyrometallurgical enrichment of the precious metal iridium. However, when hydrochloric acid is subsequently used to dissolve and separate the iron-iridium alloy, a small amount of iridium is dispersed in the hydrochloric acid solution, forming a highly acidic, high-salinity hazardous waste stream.

[0005] There are few relevant literature reports on how to enrich trace precious metals from high-acidity and high-salt hazardous waste tail liquid. In view of this, the present invention is proposed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for enriching iridium from a high-acidity and high-salt iridium-containing solution. The method selects a resin with good selectivity for iridium, and by controlling the resin adsorption parameters, low-content iridium is selectively separated from other impurities, thereby enriching low-concentration precious metal iridium.

[0007] The present invention adopts the following technical solutions: A method for enriching iridium from a high-acidity, high-salt iridium-containing solution comprises the following steps: Step 1, ion exchange resin adsorption: the feed liquid is adsorbed by LS-32 chlorine type resin, and the obtained ion exchange adsorption liquid is sent for sample detection; Step 2, pure water washing: using pure water as a detergent to elute other metal ions except iridium to obtain an iridium-loaded resin; Step 3, high temperature ashing: ashing the iridium-loaded resin at high temperature to obtain iridium-enriched slag.

[0008] In an optional embodiment, the height-to-diameter ratio of the LS-32 chlorine-type resin in step 1 is 8:1.

[0009] In an optional embodiment, two LS-32 chlorine-type resin columns connected in series are used for two-stage adsorption in step 1, with each resin column filled with 5 L of resin.

[0010] In an optional embodiment, in step 1, the flow rate of the feed liquid in the resin column is controlled to be 2 BV / h.

[0011] In an optional embodiment, the amount of the feed liquid in step 1 is 10 L.

[0012] In an optional embodiment, the amount of pure water used in step 2 is 20 L.

[0013] In an optional embodiment, in step 2, the pure water flow rate in the resin column is controlled to be 4 BV / h.

[0014] In an optional embodiment, the ashing temperature in step 3 is 850° C. and the ashing time is 4 hours.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses an ion exchange method to separate low-content precious metal iridium present in a high-acidity, high-salt solution from other high-content metal ions. After ion exchange adsorption, the iridium content in the liquid is less than 8 ppm, the iridium adsorption rate is greater than 95%, and the iridium content in the enriched iridium slag is higher than 2000 ppm, successfully realizing the comprehensive recovery of low-content iridium in a high-acidity, high-salt hydrochloric acid solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a flow chart of the method for enriching iridium from a high-acidity and high-salt iridium-containing solution. DETAILED DESCRIPTION

[0017] To facilitate understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Example 1

[0018] The main components of the high-acidity, high-salt iridium-containing solution (feed solution) in this embodiment are shown in Table 1: Table 1 Main components of the solution Element Ir Fe Cr Cu Na Ni Ca Ti Mn Al Mg Zn Feed liquid (ppm) 230 19583.1 190.7 275.1 245.8 141.4 98.9 95.7 57.4 24.9 7.2 1.8 A method for enriching iridium from a high-acidity, high-salt iridium-containing solution comprises the following steps: Step 1, ion exchange resin adsorption: Use a peristaltic pump to pass all 10L of feed liquid through LS-32 chloride-type resin for adsorption (use two resin columns with a height-to-diameter ratio of 8:1 in series for two-stage adsorption, and each resin column is filled with 5L of resin). Control the feed liquid flow rate in the resin column at 2BV / h, and send the obtained ion exchange adsorption liquid for sampling and testing; Step 2, pure water washing: Use pure water as a detergent to elute other metal ions except iridium; measure 20L of pure water, and control the pure water flow rate in the resin column to 4BV / h by a peristaltic pump to obtain an iridium-loaded resin; Step 3, high-temperature ashing: the iridium-loaded resin is ashed in a high-temperature furnace at an ashing temperature of 850° C. for 4 hours to obtain iridium-enriched slag.

[0019] After the process of Example 1, the changes of various metal ions in the ion adsorption liquid and the washing liquid are shown in Table 2: Table 2 Main components in the ion adsorption solution and the washing solution (unit: ppm) Element Ir Fe Cr Cu Na Ni Ca Ti Mn Al Mg Zn Adsorption liquid 8 2538.9 129.1 225.3 212 100.6 90.5 60.7 35.8 13.5 6.8 0.6 detergent -- 7730 23.2 12.3 8.3 10.7 3.1 6.7 5.7 -- 2.8 -- Comparing the data in Table 1 and Table 2, through step 1, the iridium adsorption rate is greater than 95%, the iron adsorption rate is 86%, and the adsorption rates of other metal ions are relatively low, successfully achieving the separation of iridium iron from other metal ions; through step 2, the separation of iridium and iron is achieved; through step 3, the enrichment of iridium metal in high-acidity and high-salt hydrochloric acid solution is finally achieved. Example 2

[0020] The difference from Example 1 is that the feed liquid in step 1 is 20 L. Example 3

[0021] The difference from Example 1 is that step 1 is primary ion adsorption. Example 4

[0022] The difference from Example 1 is that in step 1, the height-to-diameter ratio of the resin column is 5:1. Example 5

[0023] The difference from Example 1 is that in step 2, the flow rate of the feed liquid in the resin column is controlled to be 4 BV / h.

[0024] The iridium content in the solution after ion adsorption obtained in steps 2 to 5 was measured respectively. The results are shown in Table 3.

[0025] Table 3 Results of iridium content in liquid after ion adsorption Example 1 Example 2 Example 3 Example 4 Example 5 Iridium adsorption rate 95.3 86 89 91 80 Comparing Example 1 with Examples 2, 3, 4, and 5, it can be seen from the data in Table 3 that Example 1 has the highest adsorption rate, indicating that the parameters of Example 1, such as the amount of processed liquid, the number of adsorption stages, the aspect ratio, and the adsorption flow rate, are optimal. Example 6

[0026] The difference from Example 1 is that the amount of pure water in step 3 is 10 L.

[0027] The iridium-loaded resins obtained in Example 1 and Example 6 were subjected to high-temperature ashing, with the ashing temperature being 850° C. and the ashing time being 4 h. The iridium-enriched slag obtained was tested and analyzed. The iridium content in the iridium-enriched slag in Example 1 was greater than that in Example 6, indicating that the amount of pure water required for washing the resin in Example 6 was insufficient, and complete separation of iron and iridium was not achieved.

[0028] The above description is only for better explanation of the embodiments of the present invention and is not intended to limit the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are intended to be within the scope of the present invention.

Claims

1. A method for enriching iridium from a high-acidity, high-salt iridium-containing solution, characterized in that: The following steps are involved: Step 1, ion exchange resin adsorption: the feed liquid is adsorbed by LS-32 chlorine type resin, and the obtained ion exchange adsorption liquid is sent for sample detection; Step 2, pure water washing: using pure water as a detergent to elute other metal ions except iridium to obtain an iridium-loaded resin; Step 3, high temperature ashing: ashing the iridium-loaded resin at high temperature to obtain iridium-enriched slag.

2. The method for enriching iridium from a high-acidity, high-salt iridium-containing solution according to claim 1, characterized in that: The height-to-diameter ratio of the LS-32 chlorine-type resin in step 1 is 8:

1.

3. The method for enriching iridium from a high-acidity, high-salt iridium-containing solution according to claim 2, characterized in that: In step 1, two LS-32 chlorine-type resin columns connected in series were used for two-stage adsorption, with each resin column filled with 5 L of resin.

4. The method for enriching iridium from a high-acidity, high-salt iridium-containing solution according to claim 3, characterized in that: In step 1, the flow rate of the liquid in the resin column is controlled to be 2 BV / h.

5. The method for enriching iridium from a high-acidity, high-salt iridium-containing solution according to claim 1, characterized in that: The amount of the feed liquid in step 1 is 10L.

6. The method for enriching iridium from a high-acidity, high-salt iridium-containing solution according to claim 1, characterized in that: The amount of pure water used in step 2 is 20L.

7. The method for enriching iridium from a high-acidity, high-salt iridium-containing solution according to claim 1, characterized in that: In step 2, the pure water flow rate in the resin column is controlled to be 4 BV / h.

8. The method for enriching iridium from a high-acidity, high-salt iridium-containing solution according to claim 1, characterized in that: The ashing temperature in step 3 is 850° C. and the ashing time is 4 h.

Images